generalize StablePay to support multiple Djed/Gluon stablecoins and ERC20 base assets

[aniket866]

• System : Generalized the architecture to support multiple stablecoin deployments per network via an array-based configuration structure.

Protocol : Integrated Djed Isis/Tefnut protocols and new Oracle types (Chainlink, API3, HebeSwap) into the core SDK logic.

ERC20 Base Assets: Implemented a mandatory "Approve" transaction flow for non-native assets to handle ERC20-backed stablecoin purchases.

UI/Core Alignment: Updated TokenDropdown and Transaction classes to dynamically resolve and initialize specific protocol logic from the new configuration.

@Zahnentferner Please assign